A number of states remain quite close. Pat Toomey (R) is just 2.4 percentage points ahead in Pennsylvania. Maggie Hassan (D) is just 3.7 points ahead in New Hampshire. So even outside the window that we consider a "toss-up" - a lead of 2 points or less for either candidate - you have a number of races that are still quite close. Indeed, one of the few bright spots for the GOP this cycle is that most Republicans would have feared much worse for the Senate if they knew six months ago just how badly the Trump campaign was doing.
But we're starting to see several factors that could shift the balance. Democrats are doing really well in early voting in a number of states. Trump has good states too. But they're not the right states. As this new AP analysis shows, Trump is doing well in Ohio, Iowa and Georgia. Clinton is significantly over-performing in Florida, North Carolina, Maine, Arizona, Colorado and Nevada. We're used to thinking of Ohio as one of the two quintessential swing states. But this year Clinton has lots of paths to victory without Ohio. What's more, Ohio has seemed like a senate lost cause for the Democrats for a while. On the other hand, Nevada and North Carolina and extremely tight races and Arizona and Florida might also come into play if Democrats and Clinton keep picking up steam in the final two weeks.
On top of those you have Pennsylvania and New Hampshire where there are extremely close races.
The upshot is that you have a handful of extremely close races in states Clinton is either a) over-performing in early voting or b) expected to win by big margins, in some cases both. In tight races that gives the Democratic senate candidate a significant though by no means determinative advantage. We also seem to be seeing the first signs of the Democrats dramatically stronger ground game coming into play - one sign is those early voting numbers. More anecdotally, I think we're seeing some signs of de-motivation of Trump supporters, driven to some degree by Trump himself. People have been rightly outraged by Trump's hinting that he may not accept the results if he loses the election. But most people can see that that means: Trump expects to lose, which is of course highly demoralizing. It may not matter for him if Trump demoralizes his supporters. He seems highly likely to lose in any case. But incumbents in North Carolina, New Hampshire, Pennsylvania and possibly
Of course, it would be even better for Democrats if they were over-performing in Iowa and Ohio too. But in both of those states Republican senate candidates have opened up big leads over their Democratic opponents. Big Clinton wins in those states probably wouldn't be enough to help the Senate candidates. There is an extremely close race in Missouri. Roy Blunt has just a .7 percentage point lead. But here the logic works in the opposite direction. Since Missouri is quite likely to go Trump and since Democrats likely haven't invested much effort there, the natural tilt of the state makes me think Blunt will end up pulling it out. Of all the super close states though, most are in states where Clinton has expanding leads and where the Democrats have been invested resources for over a year.